What you earn depends on the rate, your balance, and how long you leave the money there
The amount of interest you earn in a savings account is calculated by multiplying your balance by the annual percentage yield (APY), then dividing by the number of days in a year. If you have $10,000 in an account paying 4.50% APY, you earn roughly $450 per year — but the actual monthly deposit to your account is smaller because interest compounds daily or monthly depending on the bank's terms.
The real number that matters is the APY, not the interest rate. APY includes the effect of compounding, so it shows you the true annual return. A bank advertising "4.50% APY" will pay you more than one advertising "4.50% interest rate" because the second figure does not account for how often interest is added to your balance.
Your earnings also depend on whether your balance stays steady or changes. If you deposit $5,000 and leave it untouched for a year at 4.50% APY, you earn $225. If you add $500 each month, your total earnings will be higher because each deposit earns interest for the remaining months of the year.
Key Takeaways
- Interest earned equals your balance multiplied by the APY, so a $10,000 balance at 4.50% APY earns roughly $450 per year.
- APY is the only rate you should compare between banks because it includes the effect of compounding; a higher APY always means more money in your pocket.
- Current savings account rates range widely depending on the bank and account type, so comparing rates across providers can add hundreds of dollars to your annual earnings.
- Money market accounts and high-yield savings accounts typically pay more than traditional savings accounts at the same bank.
How compounding affects your total earnings
Compounding means the bank pays interest on your interest. If your account compounds daily, the bank calculates interest each day based on your current balance (including yesterday's interest), then adds that day's earnings to your account. Over a year, daily compounding produces slightly more money than monthly compounding at the same APY.
The difference is small for most balances. On $10,000 at 4.50% APY, daily compounding versus monthly compounding might earn you an extra $1 or $2 over a year. But on larger balances or higher rates, the gap widens. The takeaway: APY already reflects the compounding method, so you do not need to calculate it separately — just compare APYs directly.
Why rates vary so much between banks
Online banks typically pay higher rates than brick-and-mortar banks because they have lower overhead costs. A bank with no physical branches can pass those savings to depositors through better rates. As of early 2024, online banks were offering rates between 4.00% and 5.35% APY on high-yield savings accounts, while traditional banks often paid 0.01% to 0.50% on regular savings accounts.
Rates also change based on what the Federal Reserve does. When the Fed raises its benchmark rate, banks usually raise savings rates within weeks or months. When the Fed cuts rates, banks cut savings rates more slowly — sometimes not at all if they are trying to retain deposits. This means the "best" rate today may not be the best rate in six months.
Account type matters too. Money market accounts sometimes pay more than savings accounts at the same bank because they require a higher minimum balance or limit how often you can withdraw. Certificates of deposit (CDs) lock your money away for a set term and pay more than savings accounts in exchange for that restriction.
Comparing what different account types earn
| Account Type | Typical APY Range (Early 2024) | Withdrawal Limits | Minimum Balance |
|---|---|---|---|
| Traditional savings account | 0.01% to 0.50% | Usually 6 per month | Often $0 to $100 |
| High-yield savings account | 4.00% to 5.35% | Usually unlimited | Often $0 to $25,000 |
| Money market account | 3.50% to 5.00% | Usually 6 per month | Often $2,500 to $25,000 |
| 3-month CD | 4.50% to 5.25% | None until maturity | Often $500 to $2,500 |
| 12-month CD | 4.75% to 5.50% | None until maturity | Often $500 to $2,500 |
The difference in earnings is substantial. On a $50,000 balance held for one year, a traditional savings account at 0.25% APY earns $125, while a high-yield savings account at 4.75% APY earns $2,375 — a difference of $2,250. That gap grows larger with bigger balances or longer time horizons.
How to calculate your own earnings
Use this formula: (Balance × APY) ÷ 365 × number of days = interest earned. For a $25,000 balance at 4.50% APY over 90 days: ($25,000 × 0.045) ÷ 365 × 90 = $277.40.
Most banks show you the projected annual earnings on their website before you open an account. You can also use an online savings calculator by entering your balance, the APY, and the time period. These calculators account for compounding automatically, so the result is more accurate than the simple formula above if you are comparing accounts with different compounding schedules.
If you are adding money regularly (like $500 per month), the calculation becomes more complex because each deposit earns interest for a different length of time. A savings calculator handles this; the simple formula does not.
What happens to your earnings when rates drop
Banks can change savings rates at any time without notice. If you are earning 4.75% APY and the Fed cuts rates, your bank may drop your rate to 4.00% within a few weeks. Your existing balance does not disappear, but your monthly earnings shrink immediately.
This is why some people move money between banks when rates change. If your current bank drops to 3.50% and another bank is offering 4.50%, moving your balance could earn you an extra $500 per year on a $50,000 deposit. The trade-off is the time it takes to open a new account and transfer funds, usually three to five business days.
CDs protect you from this risk for their term. If you lock $50,000 into a 12-month CD at 5.25% APY, you earn $2,625 no matter what happens to rates during those 12 months. The downside: you cannot access the money without paying an early withdrawal penalty, usually equal to a few months of interest.
Taxes on savings account interest
Interest you earn is taxable income. If you earn $500 in interest during a calendar year, you must report it on your tax return. Your bank will send you a Form 1099-INT if you earn $10 or more in interest during the year, though you may owe taxes on smaller amounts depending on your situation.
The tax you owe depends on your overall income and tax bracket. If you are in the 22% tax bracket and earn $500 in interest, you owe roughly $110 in federal tax on that interest. This reduces your real after-tax earnings to $390. High-yield savings accounts still come out ahead of traditional accounts even after taxes, but the gap is smaller than the APY difference suggests.
Frequently Asked Questions
Can I earn interest on money I withdraw before the end of the year?
Yes. Interest is calculated daily based on your balance each day. If you deposit $10,000 on January 1 and withdraw $5,000 on July 1, you earn interest on $10,000 for 181 days and on $5,000 for the remaining 184 days. The bank calculates this automatically.
Is there a limit to how much interest I can earn in a savings account?
No limit exists on the amount of interest you can earn. The only limits are on how much you can deposit (usually none) and how often you can withdraw (typically six times per month for savings and money market accounts, though this rule is less strictly enforced now).
What if I move my money to a different bank — do I lose the interest I already earned?
No. Interest earned up to the day you withdraw belongs to you. When you transfer to another bank, you receive your full balance including all accrued interest. The new bank then starts calculating interest based on your new balance at their rate.
Do I earn more interest if I keep a larger balance in my account?
Yes, directly proportional. A $50,000 balance earns twice as much as a $25,000 balance at the same APY. Some banks offer tiered rates where larger balances earn slightly higher APYs, but this is uncommon among high-yield accounts.
How often should I check rates to make sure I am earning the best amount?
Rates change frequently, especially when the Federal Reserve adjusts its benchmark rate. Checking rates quarterly or when you hear about Fed changes is reasonable. If your current bank drops significantly below competitors, moving your balance can be worth the effort.